Late Shifting, 300D auto-transmission

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richard wagner - 26 Apr 2005 00:02 GMT

Just got this 300TD with 200,000 miles on it. The tranny was overhauled
about 60,000 miles ago. Seems to me the transmission is quite late in
shifting. The engine is revving beyond the shift marks on the speedometer.
I usually have to let off on the accelerator to get it to shift earlier.

Anyone know where the linkage adjustments are?

Thanks, R.

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ChrisH - 26 Apr 2005 00:26 GMT

Sounds like a vacuum leak.

Chris

> Just got this 300TD with 200,000 miles on it. The tranny was overhauled
> about 60,000 miles ago. Seems to me the transmission is quite late in
[quoted text clipped - 4 lines]
>
> Thanks, R.

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T.G. Lambach - 26 Apr 2005 02:28 GMT

You failed to say what year so this suggestion is for an early '80s
model. At the top rear of the engine is the transmission's pressure rod
(or cable) connection to the throttle linkage. If its disconnected the
transmission will up shift very quickly and at low speeds. Your car
seems to be the opposite.

The adjustment of the pressure rod (or cable) is to pop its ball socket
off of its attachment pin on the throttle linkage at the top rear of the
engine. Gently pull the rod (or cable) to its maximum and gently release
it. The resulting position will be its "natural position".

The adjustment is correct if you can then reattach the pressure rod's
ball socket to its pin WITHOUT moving the rod (or cable). But if that's
not possible rod's length should be adjusted so it CAN be attached
without movement from its natural position. If a cable, the adjustment
is made on the nut that secures the cable - the outer case is moved and
the inner core follows.

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richard wagner - 30 Apr 2005 19:40 GMT

Many thanks for your expert advice. The car is a 1980 300TD and the Rod
was adjusted to it's minimum length. I measured the overall length and
bent
the rod into a more pronounced S curve then adjusted the threads to make it
shorter than when removed by 3 thurns. This has improved the condition
by a great lot. Will be doing some more testing on the next trip to a level
highway.
Thanks again. Richard

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richard wagner - 21 May 2005 05:23 GMT

The Vacuum pump failed on the way home from a 200 mile trip. Since the
pump was probably starting to fail and giving little vacuum, it probably
was a contributing factor in the late shifting earlier on.
With the vacuum absent and the vacuum modulator not functioning, the
automatic tranny shifted as if the pedal was down to the floor. Needed
very careful attention to traffic since the power assist to brakes was also
missing.

Will dig into the pump repair soon. Stay tuned.

Richard

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